1. Field of the Invention
This invention relates to a high-speed battery charging device having a control circuit, and more particularly to such a device and control circuit which quickly charges a battery at a high charging rate where the battery is in a low charged state, and which provides a trickle charge where the battery is in a fully charged state.
Prior art battery charging devices have the disadvantage that it takes too much time to charge, because the battery is charged by too small a current. Such low speed charging of the battery is inconvenient and is disadvantageous because of inefficient use of energy.
A device for charging a battery at a high speed has been invented to solve the disadvantages caused by the above low speed charging of the battery. However, the conventional device that quickly charges the battery only at a high charging rate does not prevent the battery from being overcharged. Thus, the battery is overcharged due to continual charging, though the battery is already fully charged. So the above disadvantage causes the life span of the battery to become shortened and energy is wasted by being overcharged.